Effects of rapeseed particle size and feed form on growth, nutrient digestibility, and gut physiology in weaned piglets*

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
Phenol
cecum	0.473	0.463	0.490	0.514	0.505	0.483	0.476	0.898	0.131	0.376
colon	0.478 a	0.429 b	0.424 b	0.423 b	0.452 ab	0.473 a	0.015	0.799	0.527	0.001
p-Cresol
cecum	4.20	4.56	3.95	4.39	4.09	4.02	0.366	0.246	0.710	0.301
colon	10.31	12.95	10.70	12.31	11.43	10.55	0.559	0.419	0.909	0.342
Indole
cecum	6.19	6.51	6.90	6.54	6.39	6.41	0.180	0.279	0.559	0.089
colon	6.45	7.01	6.86	6.85	6.63	6.86	0.309	0.457	0.971	0.103

Morphometric indices of the ileum (n=8)

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
Villus length (μm)	348.16	358.76	390.16	376.49	365.03	348.16	0.743	0.927	0.904	0.291
Villus width (μm)	132.92	144.27	134.72	139.04	138.29	141.26	0.896	0.763	0.708	0.616
Crypt depth (μm)	93.75 b	103.50 ab	110.38 ab	101.45 b	97.57 b	120.73 a	0.030	0.008	0.408	0.326
Surface area (μm²)	1471.4	1647.5	1687.3	1658.5	1610.1	1583.4	0.939	0.878	0.902	0.608

Performance results of piglets (n=8)

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
IBW 0 d (kg)	12.74	12.59	12.69	12.53	12.50	12.44	0.995	0.974	0.579	0.978
BW 14 d (kg)	19.61	19.28	19.51	20.45	20.21	20.40	0.524	0.863	0.054	0.996
FBW 28 d (kg)	28.71	27.86	28.99	30.26	29.94	30.95	0.157	0.476	0.012	0.951
DWG (kg/day)
0–14 d	0.491 ab	0.476 b	0.486 b	0.568 a	0.551 ab	0.569 a	0.027	0.803	<0.001	0.988
15–28 d	0.650	0.613	0.678	0.701	0.695	0.753	0.209	0.291	0.034	0.916
0–28 d	0.571 bc	0.546 c	0.583 bc	0.635 ab	0.624 ab	0.661 a	0.007	0.276	<0.001	0.935
DFI (kg)
0–14 d	0.879	0.861	0.856	0.881	0.838	0.866	0.832	0.466	0.854	0.775
15–28 d	1.20	1.25	1.23	1.22	1.23	1.28	0.870	0.569	0.663	0.786
0–28 d	1.04	1.06	1.04	1.05	1.04	1.07	0.959	0.883	0.769	0.711
FCR (kg/kg)
0–14 d	1.80 ab	1.82 a	1.78 ab	1.59 bc	1.53 c	1.65 c	0.011	0.923	<0.001	0.845
15–28 d	1.86	2.04	1.82	1.78	1.86	1.72	0.261	0.158	0.119	0.828
0–28 d	1.83 ab	1.94 a	1.80 abc	1.68 bc	1.68 bc	1.62 c	0.007	0.278	<0.001	0.667

Physical parameters of the liver, sialic acid and ammonia concentration, digesta pH and viscosity in the colon, ileum, and cecum (n=8)

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
Liver weight (g)	952.34 c	1011.9 abc	989.32 bc	1050.0 abc	1131.0 a	1106.2 ab	0.026	0.225	0.002	0.959
Liver/BM ratio (kg/kg)	0.033	0.036	0.034	0.035	0.038	0.036	0.093	0.033	0.105	0.999
Sialic acid (mg/L)
colon	837.70	941.90	981.10	1092.1	1075.6	875.00	0.612	0.803	0.353	0.343
Ammonia (mmol/L)
ileum	6.63 bc	8.63 ab	5.90 c	9.48 a	8.37 ab	8.94 a	0.008	0.411	0.003	0.045
cecum	10.60	8.26	7.58	9.86	8.67	9.60	0.469	0.235	0.550	0.492
pH
ileum	5.91 ab	5.55 bc	5.06 c	6.32 a	6.29 a	6.33 a	<0.001	0.123	<0.001	0.070
cecum	6.38	6.07	5.95	5.94	5.80	6.28	0.077	0.291	0.356	0.033
colon	6.19	6.19	6.23	6.41	6.37	6.34	0.753	0.991	0.125	0.927
Viscosity (cP)
ileum	2.08 ab	2.54 a	2.57 a	1.67 b	1.59 b	1.53 b	0.002	0.664	<0.001	0.289

Chemical composition of rapeseed used in the experiments (% in feed) (n=2)

	Content
Dry matter	90.01
Crude protein	20.05
Ether extract	43.70
Crude ash	3.88
Acid detergent fiber	18.81
Neutral detergent fiber	28.80

Essential amino acids

Threonine	0.9
Valine	1.01
Methionine	0.4
Isoleucine	1.42
Leucine	1.44
Phenylalanine	0.8
Lysine	1.2
Histidine	0.6

Non-essential amino acids

Tyrosine	0.6
Arginine	1.21
Aspartic acid	1.39
Cysteine	0.5
Proline	1.18
Serine	0.7
Glutamic acid	3.30
Alanine	0.9

Apparent ileal digestibility coefficients (%) of crude protein, dry matter, and amino acids in the diets (n=8)

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
Dry matter	95.97	96.05	95.55	97.36	96.53	96.92	0.061	0.582	0.004	0.503
Crude protein	57.21 ab	60.27 ab	63.92 a	68.18 a	50.89 b	64.32 a	0.046	0.054	0.716	0.056
Essential amino acids
threonine	62.39 b	66.55 ab	62.89 b	72.33 a	63.05 b	68.02 ab	0.042	0.350	0.054	0.042
valine	60.33	64.28	62.23	69.15	61.98	70.03	0.073	0.574	0.042	0.105
methionine	76.96	78.72	80.95	83.42	76.06	81.35	0.116	0.225	0.432	0.107
isoleucine	63.87	66.18	65.69	71.31	66.06	70.65	0.202	0.710	0.053	0.315
leucine	66.82	70.88	69.44	74.01	68.85	73.15	0.231	0.834	0.132	0.154
phenylalanine	71.09	73.83	71.94	77.02	72.91	75.92	0.375	0.951	0.118	0.319
lysine	67.56	74.12	72.61	75.49	71.75	74.19	0.195	0.674	0.208	0.082
histidine	63.29	66.14	66.15	68.47	62.00	69.62	0.436	0.477	0.548	0.281
Non-essential amino acids
tyrosine	65.81 b	69.24 ab	67.67 b	75.81 a	68.19 b	72.36 ab	0.048	0.485	0.020	0.088
arginine	74.48 b	76.95 b	76.12 b	83.65 a	79.24 ab	79.29 ab	0.033	0.584	0.004	0.188
aspartic acid	57.75	59.02	59.74	66.82	62.31	61.99	0.137	0.781	0.027	0.347
cysteine	60.11	58.34	60.67	67.85	59.91	64.12	0.564	0.514	0.225	0.747
proline	66.88 b	64.45 b	71.22 b	81.42 a	82.17 a	80.73 a	<0.001	0.918	<0.001	0.469
serine	62.34 bc	63.52 bc	60.22 c	73.79 a	67.53 abc	69.65 ab	0.002	0.215	<0.001	0.286
glutamic acid	74.98	76.30	78.10	81.32	73.91	78.81	0.294	0.379	0.465	0.233
alanine	41.42 b	44.99 b	47.06 b	58.61 a	50.87 ab	57.92 a	0.006	0.516	<0.001	0.283

Composition and nutritional value of experimental diets (%)

Components (% w/w)

	Day 1–14	Day 15–28
Soybean meal	17.00	15.50
Full-fat rapeseeds¹	5.00	10.00
Triticale	30.00	30.00
Wheat	44.04	40.53
Premix 0.5%²	0.500	0.500
Limestone	0.900	0.900
Phosphate 1-Ca	1.10	1.10
NaCl	0.330	0.340
L-Lysine HCl	0.450	0.450
DL-Methionine	0.130	0.130
DL-Threonine	0.250	0.250
TiO₂	0.300	0.300

Calculated nutritional value in dry matter

Metabolizable energy (MJ/kg)	13.70	14.08
Crude protein (%)	18.10	18.00
Digestible protein (%)	15.10	15.00
Digestible lysine (%)	1.14	1.14
Digestible methionine (%)	0.370	0.370
Digestible tryptophan (%)	0.705	0.704
Digestible threonine (%)	0.245	0.245
Ca (%)	0.783	0.787
P (%)	0.656	0.665
Digestible P (%)	0.425	0.426
Na (%)	0.150	0.150

Concentrations of short-chain fatty acids (μmol/g digesta) in the pigs’ cecal and colon digesta (n=8)

Grinding	WS	FG	CG	WS	FG	CG	P-value	P-value		Interaction

Pelleting	−	−	−	+	+	+		grinding	pelleting
Cecal
Acetic acid	37.44	37.812	43.58	46.74	48.21	42.25	0.143	0.957	0.033	0.158
Propionic acid	19.38	19.36	23.68	22.70	22.59	22.01	0.173	0.587	0.116	0.118
Isobutyric acid	0.510	0.462	0.529	0.614	0.631	0.520	0.233	0.772	0.058	0.252
Butyric acid	10.84	10.23	13.81	12.88	15.41	12.84	0.308	0.689	0.151	0.203
Isovaleric acid	0.260	0.215	0.309	0.380	0.374	0.285	0.343	0.894	0.094	0.274
Valeric acid	3.40	2.87	4.11	3.31	4.05	3.10	0.490	0.919	0.992	0.127
Colon
Acetic acid	53.49	56.76	51.94	51.48	46.96	47.04	0.271	0.633	0.045	0.495
Propionic acid	23.68	27.03	26.52	23.02	22.73	22.01	0.570	0.811	0.111	0.662
Isobutyric acid	1.39	1.52	1.32	1.45	1.11	1.16	0.409	0.529	0.202	0.340
Butyric acid	14.03	14.36	15.71	14.26	15.37	13.92	0.934	0.862	0.879	0.622
Isovaleric acid	1.39	1.55	1.35	1.57	1.135	1.12	0.630	0.584	0.423	0.428
Valeric acid	4.54	4.578	5.09	4.45	5.07	4.19	0.808	0.825	0.698	0.428

The experimental treatments

Treatment
Processing	1	2	3	4	5	6
Grinding	WS	FG	CG	WS	FG	CG
Pelleting	−	−	−	+	+	+

References

Authors

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Articles in this issue

DOI: https://doi.org/10.2478/aoas-2026-0007 | Journal eISSN: 2300-8733 | Journal ISSN: 1642-3402

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Language: English

Submitted on: Sep 10, 2025

Accepted on: Dec 11, 2025

Published on: Jun 5, 2026

Published by: National Research Institute of Animal Production

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

piglets,

Related subjects:

Zoology,

© 2026 Klaudia Mniszek, Małgorzata Kasprowicz-Potocka, Robert Mikuła, Anna Tuśnio, Dagmara Łodyga, Segun Olorunlowu, Adam Cieślak, Aleksandra Łangowska, Anita Zaworska-Zakrzewska, published by National Research Institute of Animal Production
This work is licensed under the Creative Commons Attribution 4.0 License.

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